Did you know within the Waikato-Tainui region, double vowels are used instead of the macron? You may have noticed how St Paul's spells these common words: Poowhiri, Te Reo Maaori and whaanau, and wondered why we use double vowels instead of macrons.
Here's the reason why:
When the first printing press arrived from England, Tainui was the first major tribe to begin printing publications. Since the printing press arrived with no macron, Tainui began printing double vowels to elongate the vowel sound, and from then on it became the formal spelling convention.
The use of the macron has been adopted by a number of other New Zealand tribes, which is why there is a variation in spelling.